Answer:
Substances 1 and 2
Explanation:
an element only has 1 kind of atoms :3
A substance that undergoes change during a reaction, usually from coming in contact with another substance
Answer:
It will be denatured.
Explanation:
Salivary amylase works best at pH 6.8.
At pH 2.5, its activity will decrease enormously as it becomes denatured by the high acidity of the stomach contents.
Answer:
The active ingredients in baking soda (NaHCO3) are
and 
when Baking soda reacts with Acetic acid
Molecular equation
NaHCO3(aq) + CH3COOH(aq) → Na(CH3COO)(aq) + CO2(g) +H2O(l)
Ionic equation
→ 
as
is present on both sides so it will cancel out and the net ionic equation will be
→ 
Answer: The force on the firefly
The unfortunate firefly hitting the bus does not change the velocity of the bus very much. Technically there is a change, but it's so very small and miniscule that it barely registers. To any casual observer not paying very close attention, they don't notice anything at all. So effectively the force on the firefly is a lot greater since the firefly got the worst end of the deal.
So in short, we look at the velocity of each object and see which velocity changed the most. In this case, the firefly's velocity changed from whatever speed it was flying to 0 when it stops flying all together. That's why the force is greater on the bug.